[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 260519
SWODY2
SPC AC 260518

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1118 PM CST SAT NOV 25 2006

VALID 271200Z - 281200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

A SLOW EWD PROGRESSION/DEVELOPMENT OF WRN U.S. LONG WAVE TROUGH
/ANCHORED BY VORTEX OVER THE PACIFIC NW/ IS FORECAST DURING THE DAY
TWO PERIOD WITH PERSISTENT RIDGING IN THE SE.  WITHIN THIS
REGIME...ELONGATED...LEAD SHORT WAVE TROUGH INITIALLY FROM THE MID
MO VALLEY SWWD TO THE SRN HIGH PLAINS MONDAY MORNING WILL LIFT NEWD
INTO THE UPPER GREAT LAKES WHILE STRONGER UPSTREAM SYSTEM EJECTS
FROM THE ROCKIES INTO THE GREAT PLAINS MONDAY NIGHT INTO TUESDAY
MORNING.

IN THE LOW-LEVELS...SURFACE FRONT EXTENDING FROM LOW PRESSURE OVER
SWRN KS NEWD INTO THE MIDWEST WILL LIFT NWD THROUGH THE PERIOD IN
RESPONSE TO INCREASING PRESSURE FALLS OVER THE NRN/CNTRL HIGH
PLAINS.  A WEAK LOW ATTENDANT TO THE LEAD SHORT WAVE TROUGH IS
FORECAST TO DEVELOP NEWD ALONG THIS RETREATING BOUNDARY WHILE
PRIMARY CYCLONE CONCURRENTLY DEEPENS OVER WY.  THIS STRONGER LOW IS
THEN EXPECTED TO DEVELOP GENERALLY EWD INTO SD BY TUESDAY MORNING.

...CNTRL/ERN KS THROUGH THE MID MO VALLEY...

LATEST SHORT RANGE MODEL GUIDANCE REMAINS CONSISTENT IN SUGGESTING
THAT SEPARATE CONVECTIVE EPISODES ARE POSSIBLE DURING THE DAY TWO
PERIOD.  ISOLATED/SCATTERED TSTMS /MAINLY ELEVATED/ ARE EXPECTED TO
BE ONGOING OR DEVELOP EARLY IN THE PERIOD MONDAY MORNING OVER THE
MID MO VALLEY PERHAPS INTO CNTRL IA...DRIVEN BY LOW-LEVEL WAA ALONG
NOSE OF SWLY LLJ AND DEEPER LAYER FORCING FOR ASCENT ASSOCIATED WITH
LEAD SHORT WAVE TROUGH.  OVER THE COURSE OF THE DAY...THIS ACTIVITY
IS FORECAST TO SHIFT INTO PARTS OF SRN MN/SWRN WI WITH BACKBUILDING
DEVELOPMENT POSSIBLE INTO ERN KS.  LAPSE RATES AND RESULTANT
INSTABILITY ARE EXPECTED TO REMAIN QUITE MARGINAL WITH STORMS LIKELY
REMAINING BELOW SEVERE LEVELS.

A POTENTIALLY GREATER THREAT OF ISOLATED...SEVERE STORMS WILL EXIST
DURING THE LATTER HALF OF THE PERIOD IN ADVANCE OF STRONGER SHORT
WAVE TROUGH MOVING OUT OF THE ROCKIES. BOUNDARY LAYER MOISTURE WILL
REMAIN MODEST WITH DEWPOINTS COMMONLY IN THE LOW/MID 50S. 
HOWEVER...A PLUME OF STEEPER MID-LEVEL LAPSE RATES WILL PRECEDE THIS
STRONGER IMPULSE...CONTRIBUTING TO MUCAPES OF 500-900 J/KG.

TSTMS ARE FORECAST TO BECOME INCREASINGLY LIKELY AFTER 28/00Z ALONG
LEE TROUGH/WEAK DRYLINE FROM PORTIONS OF WRN OK INTO CNTRL KS. 
ACTIVITY SHOULD TEND TO INCREASE IN COVERAGE AND INTENSITY MONDAY
NIGHT ACROSS CNTRL/ERN KS INTO THE MID MO VALLEY AS STRONGER DYNAMIC
FORCING OVERSPREADS REGION.  FORECAST SOUNDINGS INDICATE THAT
VERTICAL SHEAR PROFILES WILL BE QUITE SUPPORTIVE OF
ORGANIZED/ROTATING STORMS CAPABLE OF SEVERE HAIL AND LOCALLY
DAMAGING WINDS.  GIVEN THAT THIS GREATEST STORM THREAT WILL EXIST
DURING THE NIGHTTIME HOURS...PRIMARY UNCERTAINTIES ARE DEGREE OF
INSTABILITY AND WHETHER OR NOT STORMS WILL REMAIN ROOTED IN BOUNDARY
LAYER OR BECOME SLIGHTLY ELEVATED.  THEREFORE...ONLY LOW SEVERE
PROBABILITIES HAVE BEEN INCLUDED.

..MEAD.. 11/26/2006